Electrolyte for aqueous zinc-bromine battery containing bromine complexing agent and metal ion additive, and aqueous zinc-bromine non-flow battery containing same

Abstract

Provided is an electrolyte including a bromine complexing agent and a metal ion additive. The electrolyte is prepared by inputting zinc bromide (ZnBr2) salt, a bromine complexing agent, and a metal ion additive containing Mn to DI water. The bromine complexing agent prevents a crossover phenomenon by capturing bromine to alleviate self-discharge at a positive electrode, and the metal ion additive inhibits the formation of zinc dendrites on a negative electrode through an electrostatic shielding effect. Accordingly, battery performance may be improved by a synergistic effect generated in a positive electrode and a negative electrode by the bromine complexing agent and the metal ion additive.

What is claimed is: 
     
         1 . An electrolyte for a zinc-bromine aqueous battery, comprising:
 zinc bromide (ZnBr 2 ) salt, a bromine complexing agent, and a metal ion additive.   
     
     
         2 . The electrolyte of  claim 1 , wherein the bromine complexing agent is one or more selected from the group consisting of 1-ethylpyridinium bromide ([C 2 Py]Br,1-EpBr), 1-methylpyrrolidin-1-ium hydrobromide ([HMP]Br), 1-ethyl-1-methylpyrrolidin-1-iumbromide ([C 2 MP]Br)(=[MEP]Br), 1-n-butyl-1-methylpyrrolidin-1-iumbromide ([C 4 MP]Br), 1-n-hexyl-1-methylpyrrolidin-1-iumbromide ([C 6 MP]Br), 1-ethyl-1-methylmorpholin-1-iumbromide ([C 2 MM]Br)(=[MEM]Br), 1-n-butyl-1-methylmorpholin-1-iumbromide ([C 4 MM]Br), pyridin-1-ium hydrobromide ([HPy]Br), 1-n-butylpyridin-1-iumbromide ([C 4 Py]Br), 1-n-butylpyridin-1-iumchloride ([C 4 Py]Cl), 1-n-hexylpyridin-1-iumbromide ([C 6 Py]Br), 1-n-hexylpyridin-1-iumchloride ([C 6 Py]Cl), 4-methylpyridine hydrobromide ([H 4 MPy]Br), 1-ethyl-4-methylpyridine hydrobromide ([C 24 MPy]Br), 1-n-butyl-4-methylpyridine hydrobromide ([C 44 MPy]Br), 1-n-hexyl-4-methylpyridine hydrobromide ([C 23 MPy]Br), 3-methylpyridine hydrobromide ([H 3 MPy]Br), 1-ethyl-3-methylpyridinebromide ([C 23 MPy]Br), 1-n-butyl-3-methyl-pyridinebromide ([C 43 MPy]Br), 1-n-hexyl-3-methyl-pyridinebromide ([C 63 MPy]Br), 3-methylimidazol-1-ium hydrobromide ([HMIm]Br), 1-ethyl-3-methylimidazol-1-iumbromide ([C 2 MIm]Br), 1-ethyl-3-methylimidazol-1-iumchloride ([C 2 MIm]Cl), 1-n-propyl-3-methylimidazol-1-iumbromide ([C 3 MIm]Br), 1-n-butyl-3-methyl-imidazol-1-iumbromide ([C 4 MIm]Br), 1-n-butyl-3-methyl-imidazol-1-iumchloride ([C 4 MIm]Cl), 1-n-hexyl-3-methylimidazol-1-iumbromide ([C 6 MIm]Br), 1-n-hexyl-3-methylimidazol-1-iumchloride ([C 6 MIm]Cl), 1-methylpiperidin hydrobromide ([HMPip]Br), 1-ethyl-1-methylpiperidinbromide ([C 2 MPip]Br), 1-n-butyl-1-methylpiperidinbromide ([C 4 MPip]Br), 1-n-hexyl-1-methylpiperidinbromide ([C 6 MPip]Br), 1,1,1-trimethyl-1-n-tetradecyl ammoniumbromide ([MTA]Br), 1,1,1-trimethyl-1-n-hexadecyl ammoniumbromide ([CTA]Br), tetraethylammoniumbromide ([TEA]Br), tetra-n-butylammoniumbromide ([TBA]Br), tetra-n-octylammoniumbromide ([TOA]Br), tetra-n-octylammoniumchloride ([TOA]Cl), (polysorbate) n -1R 1 -2R 2 -3R 3  imidazolium bromide, and (polysorbate) n -1R 1 -3R 3  imidazolium bromide,
 wherein each of R1, R2 and R3 independently has a functional group with 1 to 4 carbon atoms.   
     
     
         3 . The electrolyte of  claim 1 , wherein the bromine complexing agent has a molarity of 0.1 M to 1.5 M. 
     
     
         4 . The electrolyte of  claim 1 , wherein the metal ion additive has a lower standard reduction potential than the standard reduction potential of zinc, and a higher standard oxidation potential than the standard oxidation potential of bromine. 
     
     
         5 . The electrolyte of  claim 1 , wherein the metal ion additive is a salt containing Mn. 
     
     
         6 . The electrolyte of  claim 5 , wherein the metal ion additive is one selected from the group consisting of MnSO 4 , MnCl 2 , Mn(NO 3 ) 2 , Mn 3 (PO 4 ) 2 , and Mn(CH 3 CO 2 ) 2 . 
     
     
         7 . The electrolyte of  claim 1 , wherein the metal ion additive has a molarity of 0.05 M to 0.1 M. 
     
     
         8 . The electrolyte of  claim 1 , wherein the ZnBr 2  has a molarity of 2.0 M to 3.0 M. 
     
     
         9 . An aqueous zinc-bromine non-flow battery, comprising:
 a negative electrode in which a zinc metal layer is formed on a negative electrode conductive plate and zinc reduction occurs during a charging operation;   a positive electrode in which carbon felt is formed on a positive electrode conductive plate and bromine oxidation occurs during a charging operation; and   an electrolyte charged in a space between the negative electrode and the positive electrode,   wherein the electrolyte comprises ZnBr 2 , a bromine complexing agent, and a metal ion additive.   
     
     
         10 . The battery of  claim 9 , wherein the positive electrode comprises bromine captured on the carbon graphite felt by the bromine complexing agent during the charging operation. 
     
     
         11 . The battery of  claim 9 , wherein the bromine complexing agent is one or more selected from the group consisting of 1-ethylpyridinium bromide ([C 2 Py]Br,1-EpBr), 1-methylpyrrolidin-1-ium hydrobromide ([HMP]Br), 1-ethyl-1-methylpyrrolidin-1-iumbromide ([C 2 MP]Br)(=[MEP]Br), 1-n-butyl-1-methylpyrrolidin-1-iumbromide ([C 4 MP]Br), 1-n-hexyl-1-methylpyrrolidin-1-iumbromide ([C 6 MP]Br), 1-ethyl-1-methylmorpholin-1-iumbromide ([C 2 MM]Br)(=[MEM]Br), 1-n-butyl-1-methylmorpholin-1-iumbromide ([C 4 MM]Br), pyridin-1-ium hydrobromide ([HPy]Br), 1-n-butylpyridin-1-iumbromide ([C 4 Py]Br), 1-n-butylpyridin-1-iumchloride ([C 4 Py]Cl), 1-n-hexylpyridin-1-iumbromide ([C 6 Py]Br), 1-n-hexylpyridin-1-iumchloride ([C 6 Py]Cl), 4-methylpyridine hydrobromide ([H 4 MPy]Br), 1-ethyl-4-methylpyridine hydrobromide ([C 24 MPy]Br), 1-n-butyl-4-methylpyridine hydrobromide ([C 44 MPy]Br), 1-n-hexyl-4-methylpyridine hydrobromide ([C 23 MPy]Br), 3-methylpyridine hydrobromide ([H 3 MPy]Br), 1-ethyl-3-methylpyridinebromide ([C 23 MPy]Br), 1-n-butyl-3-methyl-pyridinebromide ([C 43 MPy]Br), 1-n-hexyl-3-methyl-pyridinebromide ([C 63 MPy]Br), 3-methylimidazol-1-ium hydrobromide ([HMIm]Br), 1-ethyl-3-methylimidazol-1-iumbromide ([C 2 MIm]Br), 1-ethyl-3-methylimidazol-1-iumchloride ([C 2 MIm]Cl), 1-n-propyl-3-methylimidazol-1-iumbromide ([C 3 MIm]Br), 1-n-butyl-3-methyl-imidazol-1-iumbromide ([C 4 MIm]Br), 1-n-butyl-3-methyl-imidazol-1-iumchloride ([C 4 MIm]Cl), 1-n-hexyl-3-methylimidazol-1-iumbromide ([C 6 MIm]Br), 1-n-hexyl-3-methylimidazol-1-iumchloride ([C 6 MIm]Cl), 1-methylpiperidin hydrobromide ([HMPip]Br), 1-ethyl-1-methylpiperidinbromide ([C 2 MPip]Br), 1-n-butyl-1-methylpiperidinbromide ([C 4 MPip]Br), 1-n-hexyl-1-methylpiperidinbromide ([C 6 MPip]Br), 1,1,1-trimethyl-1-n-tetradecyl ammoniumbromide ([MTA]Br), 1,1,1-trimethyl-1-n-hexadecyl ammoniumbromide ([CTA]Br), tetraethylammoniumbromide ([TEA]Br), tetra-n-butylammoniumbromide ([TBA]Br), tetra-n-octylammoniumbromide ([TOA]Br), tetra-n-octylammoniumchloride ([TOA]Cl), (polysorbate) n -1R 1 -2R 2 -3R 3  imidazolium bromide, and (polysorbate) n -1R 1 -3R 3  imidazolium bromide,
 wherein each of R1, R2 and R3 independently has a functional group with 1 to 4 carbon atoms.   
     
     
         12 . The battery of  claim 9 , wherein the negative electrode inhibits zinc dendrite formation by capping the surface of a surface protrusion of a zinc metal layer with the metal ion additive. 
     
     
         13 . The battery of  claim 9 , wherein the metal ion additive has a lower standard reduction potential than the standard reduction potential of zinc, and a higher standard oxidation potential than the standard oxidation potential of bromine. 
     
     
         14 . The battery of  claim 9 , wherein the metal ion additive is a salt containing Mn. 
     
     
         15 . The battery of  claim 9 , wherein the metal ion additive is one selected from the group consisting of MnSO 4 , MnCl 2 , Mn(NO 3 ) 2 , Mn 3 (PO 4 ) 2 , and Mn(CH 3 CO 2 ) 2 .